The major upgraded for YN-560 III is that it comes with RF-602 and RF-603 2.4G compatible radio receivers built-in to the unit, which means you can use YN-560 III as a receiver off camera, and it can be used together with RF-602 / RF-603 transmitters on the camera, pressing the button of transmitter or the shutter release button of camera, YN-560 III can be fired. You can not only use YN-560 III as a flash, but also a flash receiver, you can use those two functions synchronously. Specification: The major upgraded for YN-560 III is that it comes with RF-602 and RF-603 2.4G compatible radio receivers built-in to the unit, which means you can use YN-560 III as a receiver off camera, and it can be used together with RF-602 / RF-603 transmitters on the camera, pressing the button of transmitter or the shutter release button of camera, YN-560 III can be fired. You can not only use YN-560 III as a flash, but also a flash receiver, you can use those two functions synchronously. Suit for: ANY Standard Hot Shoe DSLR Camera, such as Canon, Nikon, Pentax, Olympus, and so on RF-602 Transmitter ( We don't sell the transmitter separatedly, so I suggest you can buy a whole RF-602 set, and use YN-560 III as the second receiver. : ) ) RF-603 Transceiver ( The model of the transceiver depands on the camera you used. ) Circuit design Insulated Gate Bipolar Transistor (IGBT) Guide No. 5 meters (ISO 100, 105mm) Flash mode M, Multi( TRIGGERING MODE :camera set-up,S1,S2,RX) Zoom range 24, 28, 35, 50, 70, 80, 105mm Vertical rotation angle -7~90 degrees Horizontal rotation angle 0~270 degrees Power supply 4×AAsize batteries (Alkaline or Ni-MH are usable) Lighting times 100~1500 times (AA alkaline cell used) Recycle time approx 3s (AA alkaline cell used) Color temperature 5600k Flash time 1/200s~1/20000s Flash control 8 levels of output control (1/128~1/1), 29 levels of fine tuning External interface hot shoe, PC port and eternal charging port. Wireless triggering distance 100(2.4g wireless);20-25m indoor,10-15m out door (optical control), the electronic flash head zooming, sound prompt, automatically saving setting, power saving mode, overheating protection and advanced options. Additional features The electronic flash head zooming, sound prompt, automatically saving setting, power saving mode, overhearting protection and advanced options. And you can use Flash Bracket / Flash Umbrella as accessories to fit for this flash. Package Including: 1 x YN-560 III WITH METAL HOT SHOE 1 x Mini Stand 1 x Protecting case ( Black ) with Wrapped Air Bubble Sheet 1 x Manual in English and Chinese 1 x Original Box